Breast cancer (BC) is the most frequently diagnosed noncutaneous malignant disease in women worldwide, with rates on the rise in all western countries. It can currently be considered a health problem of epidemic proportions, as one to two out of every ten women will develop breast cancer during their lives. It is also the leading cause of death among women worldwide. Given the high incidence of breast cancer, early diagnosis (screening campaigns and annual reviews) and huge advancements in current diagnosis and treatment mean that the survival rate of breast cancer is high. Early diagnosis is crucial for increasing the possibility of breast-conserving treatment and cure. The treatment and monitoring of breast cancer is multidisciplinary and coordination between the surgeon (gynaecologist), oncologist, radiologist and radiation therapists is fundamental.
A number of factors can influence the development of breast cancer, such as:
- Environmental factors: food (eating vegetables, fruit, soy, etc., reduces risk); body mass (being overweight increases risk); physical activity; stress; tobacco; alcohol; radiation and electromagnetic fields.
- Hormonal factors: these are mainly related to oestrogens and their ability to stimulate cell proliferation. Thus, women who experience premature menarche, late menopause, nulliparity (women who have never had a child) and obesity have an increased risk of BC.
- Genetic factors: the majority of women with a family history of BC have a higher risk of getting the disease. However, most are sporadic and only 5-10% of breast cancers are attributable to inherited genes. Several genes linked to heredity have been identified; BRCA 1 and 2 are the most frequent and well-known.
Breast tumours can roughly be classified as:
- origin: ductal (begins in the milk ducts) and lobular (begins in the lobules)
- Infiltrating: in situ cancer (malignancies that are unable to break through the basement membrane and thus are unable to spread to other areas. this means that the treatment will be local and that supplementary treatments are unlikely to be required). infiltrating cancer (tumours that have the ability to cross the basal membrane and metastasise. this means that the cancer must be treated as a systemic disease and a full-body exam will need to be performed. a high percentage of these cases require a combination of several treatments including surgery, chemotherapy, radiotherapy, etc.).
In many cases current advances make early diagnosis of breast cancer possible. There is one diagnostic method that stands out above the rest: the mammogram. It is the test used for early diagnosis and prevention of breast cancer, also called a screening test in laymen terms, and improves the disease’s mortality and morbidity rates.
Diagnosis is most frequently subclinical, identified through a population-screening mammogram or routine annual pelvic exam and check-up. In these cases abnormal areas such as microcalcifications, suspicious lumps and changed areas are observed.
Another reason for diagnosis is the appearance of a palpable lump that the patient or gynaecologist notices.
Another is nipple discharge, usually bloody; and nipple excoriations, as well as sunken or dimpled skin or nipple.
- MAMMOGRAM (please see regular gynaecologic tests).
- BREAST ULTRASOUND (please see regular gynaecologic tests).
- FNA (fine needle aspiration): An easy and reliable technique that allows us to obtain cells for cytology. It does not require anaesthesia and is well tolerated.
- CNB (core needle biopsy): Allows us to obtain small tissue samples for further pathological examination with 100% reliability. It requires local anaesthesia and causes some discomfort that lasts for a few days
- BREAST MRI: Its main indication is to identify multifocal or multicentric disease, detect recurrences in the scar and occult carcinomas, as well as monitor women at high genetic risk. It use is increasing, especially when there is a discrepancy between other tests
- OTHER: galactography, thermography and PET/CT scan
The type of surgery used to treat breast cancer has changed as knowledge of the disease has advanced. For many years the radical mastectomy proposed in 1882 by William Stewart Halsted (excision of the entire breast, axillary lymph nodes and chest muscle), a very mutilating surgery, was standard. Advances in early diagnosis, treatment (radiotherapy, chemotherapy) and knowledge of the disease led to the creation of increasingly breast-conserving treatments (lumpectomy) and lymph nodes (sentinel node biopsy).
Surgical removal of the mammary gland: skin, nipple-areolar complex and the breast’s entire glandular tissue. The mammary gland stretches from the 2nd/3rd rib to the 6th/7th and from the midway parasternal line to the anterior axillary line. Mastectomy is still indicated in certain cases such as the elderly, who are unable to receive adjuvant treatment; and in patients with cases that pose difficult subsequent monitoring. Subcutaneous mastectomy (preservation of skin and nipple-areolar complex) has also increased as genetic factors like the BRCA 1 and 2 mutations can now be determined as prevention.
This is the partial removal of the breast with or without skin. The purpose of breast-conserving surgery is to achieve the lowest possible mutilation with a better aesthetic outcome, removing enough tissue to test for cancer, as well as maximum control of the local disease. We must ensure that the surrounding tissue does not contain cancerous cells. It is currently the most widely used technique for breast cancer. It involves performing radiotherapy on the remaining breast.
Until recently this procedure was always performed in the surgical treatment of breast cancer and involves the excision of all axillary adipose tissue (Berg level III). The entire axillary vein is dissected from where it begins at the outer edge of the pectoralis major to the lower edge of the clavicle.
A total or radical lymphadenectomy has a significant impact on women. It involves strict care for the arm and a risk of developing lymphedema in the arm, which in most cases is mild but sometimes can be so severe that it becomes disabling.
The exegesis and exam of the sentinel node is based on assessing the first lymph node that may be affected or cancerous in the case of the lymphatic spread of breast cancer. It is performed by injecting an isotopic colloid in the breast (subareolar, intratumoral, peritumoral or subdermal) with posterior scintigraphic detection. Radioactivity is subsequently located using a gamma probe during surgery. The lymph node is sent to the lab during surgery and analysed for imprints; if the test results are negative the rest of the axillary tissue can be preserved. Another analysis will be performed later.
The purpose of radiotherapy is to eradicate residual microscopic disease in the breast, thus reducing local recurrences. It is always used after breast-conserving surgery, on the chest wall in certain mastectomy cases and on lymph node chains. Radiotherapy causes an ionization of organic tissues that leads to short- and long-term side effects, making it crucial to preserve the organs under the breast. Today, morbidity is quite low as the result of new radiotherapy equipment and previous tests and simulations with CT scans and computers.
Chemotherapy treatment is based on treating the patient globally to reduce the risk of metastatic disease. Not every patient will require chemotherapy. It is important to remember that advances in this field over the past 15 years have been spectacular with amazing possibilities for success.
Several different treatment regimens and chemotherapeutic agents are used according to the characteristics of the patient, tumour and receptors, that is, each patient receives individualised treatment.
Chemotherapy may be given before surgery (neoadjuvant chemotherapy) or afterwards (adjuvant chemotherapy).
Hormone therapy involves taking an oral treatment for several years to block the oestrogen receptors on tumoral cells, resulting in a decrease risk of recurrence.